The physiology of the obese and their propensity for chronic disease has been of growing interest over the past few years. An extensive literature has begun to accumulate. The development of obesity in man is of complex etiology involving genetic and environmental components that affect regulatory and metabolic events. The presence of a large quantity of adipose tissue that requires its own blood supply, has its own metabolism, participates in the body's turnover processes, must be transported at a cost, changes the body's center of gravity, etc., must have measurable impacts on the organism. These impacts are of interest to us. We have undertaken a rather broad approach to the problem of the multiple effects of obesity on the intact organism. For the most part, we have used noninvasive approaches and because of our research environment (laboratory not situated within a medical school), we plan to continue this noninvasive emphasis. Our focus will continue to be on the physiological effects induced by exposure of the obese as compared to the lean to single and multiple stresses with which each subject volunteers to cope. Since obesity is one of the major health problems, we are interested in helping reduce the prevalence of obesity, informing the obese and the health community about the environmental and physical risks of obesity as well as suggesting ways for reducing environmental stress so as to reduce physiological strain. The specific aims of the continuing research include: 1) to improve the methods for the assessment of body fatness, 2) to assess the feasibility of cycling in water for purposes of weight reduction, and 3) to assess heat tolerance in the obese as it is related to heat activated sweat gland activity, total body sweating and forearm blood flow in a non-working arm as representative of skin blood flow.